/*
 Problem Description
There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can move only on black tiles.

Write a program to count the number of black tiles which he can reach by repeating the moves described above. 
Input
The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.

There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.

'.' - a black tile 
'#' - a red tile 
'@' - a man on a black tile(appears exactly once in a data set) 
Output
For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself). 
Sample Input
6 9
....#.
.....#
......
......
......
......
......
#@...#
.#..#.
11 9
.#.........
.#.#######.
.#.#.....#.
.#.#.###.#.
.#.#..@#.#.
.#.#####.#.
.#.......#.
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
###.###
...@...
###.###
..#.#..
..#.#..
0 0
Sample Output
45
59
6
13
 */
package com.yuan.algorithms.practice201504;

import java.util.Scanner;

public class 搜索_最大能到达的地方 {

	static int sum;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()) {
			sum = 0;
			int m = sc.nextInt();
			int n = sc.nextInt();
			if (n==0&&m==0) {
				break;
			}
			char[][] map = new char[n][m];
			int sx = 0,ey = 0;
			for (int i = 0; i < n; i++) {
				String x = sc.next();
				for (int j = 0; j < m; j++) {
					map[i][j] = x.charAt(j); 
					if (x.charAt(j)=='@') {
						sx = i;
						ey = j;
					}
				}
			}
			map[sx][ey] = '.'; 
			f(map,sx,ey);
			System.out.println(sum);
		}

	}

	private static void f(char[][] map, int sx, int ey) {
		if (sx>=map.length || ey >= map[0].length || sx<0 || ey<0) {
			return;
		}
		if (map[sx][ey]!='.') {
			return;
		}
		if (map[sx][ey]=='.' ) {
			sum++;
			map[sx][ey] = '*'; 
		}
		f(map, sx+1, ey);
		f(map, sx, ey+1);
		f(map, sx-1, ey);
		f(map, sx, ey-1);
	}

}
